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[IA64] need r29=psr *after* rsm psr.i
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Yanmin Zhang pointed out a sequence problem when saving the psr.  David
Mosberger provided this patch (which gave up a cycle).

Signed-off-by: Tony Luck <tony.luck@intel.com>
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David Mosberger-Tang authored and Tony Luck committed Apr 28, 2005
1 parent e7e965f commit 8e3e501
Showing 1 changed file with 5 additions and 6 deletions.
11 changes: 5 additions & 6 deletions arch/ia64/kernel/gate.S
Original file line number Diff line number Diff line change
Expand Up @@ -77,7 +77,7 @@ GLOBAL_ENTRY(__kernel_syscall_via_epc)
epc // B causes split-issue
}
;;
rsm psr.be // M2 (5 cyc to srlz.d)
rsm psr.be | psr.i // M2 (5 cyc to srlz.d)
LOAD_FSYSCALL_TABLE(r14) // X
;;
mov r16=IA64_KR(CURRENT) // M2 (12 cyc)
Expand All @@ -98,15 +98,14 @@ GLOBAL_ENTRY(__kernel_syscall_via_epc)
nop.i 0
;;
nop.m 0
(p6) mov b7=r18 // I0
(p6) tbit.z.unc p8,p0=r18,0 // I0 (dual-issues with "mov b7=r18"!)

nop.m 0
nop.i 0
;;
(p8) ssm psr.i
(p6) mov b7=r18 // I0
(p8) br.dptk.many b7 // B

mov r27=ar.rsc // M2 (12 cyc)
(p6) rsm psr.i // M2
/*
* brl.cond doesn't work as intended because the linker would convert this branch
* into a branch to a PLT. Perhaps there will be a way to avoid this with some
Expand All @@ -123,7 +122,7 @@ GLOBAL_ENTRY(__kernel_syscall_via_epc)
#else
BRL_COND_FSYS_BUBBLE_DOWN(p6)
#endif

ssm psr.i
mov r10=-1
(p10) mov r8=EINVAL
(p9) mov r8=ENOSYS
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